JP6786052B2 - Manufacturing method of ε-caprolactam - Google Patents

Description

The present invention relates to a method for producing ε-caprolactam, which is a raw material for polyamide.

ε-Caprolactam is an important chemical raw material used as a raw material for polyamides and the like, and is industrially produced all over the world, and most of them are used as a raw material for nylon 6 which is a polyamide.

As an industrial production method for ε-caprolactam, a production method using a Beckmann rearrangement reaction from cyclohexanone oxime with fuming sulfuric acid is widely adopted. Crude oil is the main raw material for this manufacturing method, but alternative raw materials are used due to concerns about future depletion of fossil resources and global warming caused by greenhouse gases emitted from the mining and use of fossil resources. It is necessary to develop a method for producing ε-caprolactum. In particular, the development of a method for producing ε-caprolactam from biomass, which is a renewable resource, or a substance derived from the biomass resource is required.

Patent Document 1 discloses a method for producing ε-caprolactam by reacting adipic acid with hydrogen and ammonia in the presence of a heterogeneous catalyst and tert-butanol. As disclosed in Patent Document 2 and Non-Patent Document 1, adipic acid is a substance that can be fermentatively produced from sugar and can be derived from biomass resources.

Further, Patent Document 3 discloses a method for producing ε-caprolactam by reacting muconic acid with hydrogen and ammonia in the presence of a catalyst. As disclosed in Patent Document 4, muconic acid is a substance that can be fermentatively produced from glucose and can be derived from a biomass resource.

3-oxoadipic acid is a 6-carbon dicarboxylic acid having a carbonyl group. Patent Document 5 discloses a method for fermenting and producing 3-oxoadipic acid from protocatechuic acid or vanillic acid. Non-Patent Document 2 shows that protocatechuic acid and vanillic acid can be obtained by decomposing lignin, which is a main component of plants. In addition, Non-Patent Document 3 discloses a method for fermenting and producing protocatechuic acid from glucose. From these facts, it can be said that 3-oxoadipic acid can also be derived from lignin and sugar.

Patent Document 6 discloses a method for producing 3-hydroxyadipic acid by reacting 3-oxoadipic acid with hydrogen in the presence of a catalyst and a solvent.

International Publication No. 2013/126250 Japanese Patent Publication No. 2011-515111 International Publication No. 2012/141997 U.S. Patent Application Publication No. 2013/0030215 Japanese Unexamined Patent Publication No. 2012-59 International Publication No. 2014/043182

Biotechnology and Engineering, Vol. 111, p. 2580-2586 (2011) Natural Products Reports, Vol. 28, p. 1883-1896 (2011) Journal of the American Chemical Society, Volume 117, p. 2395-2400 (1995)

Ε-Caprolactam can be produced from adipic acid by the method disclosed in Patent Document 1. However, adipic acid is considered to have low efficiency in deriving from biomass resources, and is not suitable as a raw material for ε-caprolactam of biomass resources. For example, Patent Document 2 discloses a method for fermentatively producing adipic acid from glucose, but does not describe an example in which adipic acid is actually produced, and whether or not adipic acid can be actually produced is not described. It is unknown. In general, when a substance is produced using a microorganism, it is desirable that the redox balance determined by the ratio of intracellular NADH and NAD ⁺ is maintained. However, according to the description in this document, the redox balance is maintained. It is presumed that it is difficult to produce adipic acid by this method because it is considered that the adipic acid is not maintained. Further, in the method disclosed in Non-Patent Document 1, the yield of adipic acid based on glucose is as low as 0.008 mol%.

By the method disclosed in Patent Document 3, ε-caprolactam can be produced from muconic acid. However, muconic acid has low efficiency in deriving from biomass resources and is not suitable as a raw material for ε-caprolactam. In the method disclosed in Patent Document 4, the yield of muconic acid based on glucose is as low as 30 mol%, which is not a sufficiently satisfactory value.

On the other hand, 3-oxoadipic acid can be derived from biomass resources with high efficiency. According to the method disclosed in Patent Document 5, the yield of 3-oxoadipic acid based on the lignin decomposition product protocatechuic acid or vanillic acid is 100 mol%. In the method disclosed in Non-Patent Document 3, the yield of protocatechuic acid based on glucose is 50 mol%. From the above, 3-oxoadipic acid is a substance that can be derived from a lignin decomposition product or glucose with high efficiency, and is considered to be suitable as a raw material for ε-caprolactam that can be derived from a biomass resource.

However, there has been no report on how to convert 3-oxoadipic acid to ε-caprolactam. 3-oxoadipic acid is a compound having a basic structure of a dicarboxylic acid having 6 carbon atoms similar to adipic acid and muconic acid, but as shown in Comparative Example 1 of the present specification, the method described in Patent Document 3 Was applied as is to 3-oxoadipic acid, but it was found that ε-caprolactam was not produced at all. In other words, it became clear that the method of converting muconic acid to ε-caprolactam cannot be directly applied to 3-oxoadipic acid.

An object of the present invention is to provide a method for producing ε-caprolactam from 3-oxoadipic acid, which is suitable as a biomass resource.

As a result of diligent research to solve the above problems, the present inventors have conducted a step (step 1) of mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen as shown in Scheme 1 and a step (step 1). It was found that ε-caprolactam could be produced by sequentially carrying out the steps (step 2) of reacting the product of No. 1 with hydrogen and ammonia, and the invention was completed.

That is, the present invention provides the following (1) to (11).
(1) At least one selected from the group consisting of 3-oxoadipic acid and a salt thereof is mixed with a catalyst and a solvent in the presence of hydrogen and in the substantially absence of ammonia to produce 3-hydroxyadipic acid. Ε-caprolactam comprising step 1 which is a step and step 2 which is a step of reacting 3-hydroxyadipic acid, a salt or carboxylic acid derivative thereof, which is a product of step 1, or a mixture thereof with hydrogen and ammonia. Production method.
(2) The method according to (1), wherein the solvent is an aqueous solvent or an organic solvent having a polarity value of 0 or more and 0.3 or less.
(3) The method according to (1) or (2), wherein the solvent is an organic solvent mainly containing at least one selected from the group consisting of an ether solvent and an ester solvent.
(4) Item 1 in any one of (1) to (3), wherein the solvent is an organic solvent mainly containing at least one selected from tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diglyme, and ethyl acetate. The method described.
(5) The method according to any one of (1) to (4), wherein the step 1 is performed under the conditions shown in (i) or (ii) below.
(I) Reaction temperature 0 ° C or higher and 50 ° C or lower in an aqueous solvent (ii) Reaction temperature 0 ° C or higher and lower than 75 ° C in an organic solvent with a polarity value of 0 or higher and 0.3 or lower (6) The step 2 is performed in the presence of a catalyst. The method according to any one of (1) to (5), which is carried out in 1.
(7) The catalyst of steps 1 and / or 2 comprises one or more metals selected from the group consisting of palladium, platinum, ruthenium, rhodium, rhenium, nickel, iridium, osmium, copper and chromium. The method according to any one of (1) to (6).
(8) The production method according to (7), wherein the metal is supported on at least one carrier selected from the group consisting of alumina, carbon, silica, titania, zirconia, tantalum oxide, niobium oxide, and zeolite. ..
(9) The production method according to any one of (1) to (8), wherein the partial pressure of hydrogen in steps 1 and 2 is 0.1 MPa or more and 10 MPa or less at room temperature and gauge pressure.
(10) The production method according to any one of (1) to (9), wherein the reaction temperature in the step 2 is 150 ° C. or higher and 280 ° C. or lower.
(11) At least one selected from the group consisting of 3-oxoadipic acid and a salt thereof is used as a catalyst in the presence of hydrogen and in the substantially absence of ammonia under the conditions shown in (i) or (ii) below. A method for producing 3-hydroxyadipic acid by mixing.
(I) Reaction temperature 0 ° C or higher and 50 ° C or lower in an aqueous solvent (ii) Reaction temperature 0 ° C or higher and lower than 75 ° C in an organic solvent with a polarity value of 0 or higher and 0.3 or lower.

According to the present invention, ε-caprolactam can be produced from 3-oxoadipic acid, which can be derived from biomass resources with high efficiency. Since 3-oxoadipic acid can be derived from various biomass resources (lignin and sugar), the present invention is useful for the stable production of ε-caprolactam derived from biomass resources.

Further, according to the present invention, 3-oxoadipic acid to 3-hydroxyadipic acid can be produced in a short process while suppressing the by-production of levulinic acid.

Hereinafter, the present invention will be described in more detail.

In the present invention, the biomass resource means a renewable organic resource derived from an organism, and refers to a resource composed of an organic substance produced by a plant immobilizing carbon dioxide using solar energy. Specifically, corn, sugar cane, potatoes, wheat, rice, soybeans, pulp, kenaf, rice straw, straw, bagasse, corn stover, switchgrass, weeds, used paper, wood, charcoal, natural rubber, cotton, soybean oil. , Palm oil, safflower oil, kenaf oil and the like.

In the present invention, the substance derived from the biomass resource means a substance derived from the above-mentioned biomass resource by fermentation, chemical conversion, or the like, a substance that can be derived, or a substance derived.

The 3-oxoadipic acid used in the present invention is a substance that can be derived from biomass resources as described above. Specifically, as shown in Scheme 2, a method for fermentatively producing 3-oxoadipic acid from protocatechuic acid or vanillic acid, which is derived from lignin or glucose, can be exemplified. For example, as described in Non-Patent Document 2, protocatechuic acid or vanillic acid can be produced by decomposing lignin using Pseudomonas paucimobilis, Sphingomonas paucimovis, or the like. In addition, as described in Non-Patent Document 3, 50 mol% of protocatechuic acid can be fermented and produced from glucose using Escherichia coli into which the aroZ gene of Klebsiella pneumoniae has been introduced. From the protocatechuic acid or vanillic acid thus obtained, 3-oxoadipic acid can be fermented and produced in a yield of 100 mol% using the recombinant Pseudomonas putida as described in Patent Document 5. it can.

The present invention is characterized in that 3-oxoadipic acid derived from a biomass resource can be used as a raw material, but 3-oxoadipic acid derived from a fossil resource such as petroleum can also be used as a raw material.

The 3-oxoadipic acid used in the present invention can be used in a free form or in a salt state, or in a mixture of a free form and a salt. The salt may be a monovalent salt or a divalent salt, and examples of the monovalent salt include 3-oxoadipate monoammonium salt, 3-oxoadipate monolithium salt, and 3-oxoadipate monosodium salt. Examples thereof include 3-oxoadipate monopotassium salt, and examples of the divalent salt include 3-oxoadipate diammonate salt, 3-oxoadipate dilithium salt, 3-oxoadipate disodium salt, and 3-oxoadipate. Examples thereof include dipotassium oxoadipate, magnesium 3-oxoadipate, and calcium 3-oxoadipate. Mixtures of these different salts can also be used.

The method for producing ε-caprolactam of the present invention is a step 1 of mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen, and a step of reacting the product of step 1 with hydrogen and ammonia. It is characterized by including step 2.

The solvent used in step 1 is not limited, but is an alcohol solvent such as methanol, ethanol, propanol and butanol, a halogen solvent such as carbon tetrachloride, dichloromethane and chloroform, and a fat such as pentane, hexane, heptane, octane and decane. Group hydrocarbon solvents, aromatic hydrocarbon solvents such as benzene, toluene and xylene, ether solvents such as dimethyl ether, diethyl ether, 1,2-dimethoxyethane, diglyme, tetrahydrofuran and dioxane, methyl acetate, ethyl acetate, acetic acid Ester-based solvents such as n-propyl and n-butyl acetate, organic solvents such as γ-butyrolactone, N-methylpyrrolidone, and dimethylsulfoxide, and water or water as the main component (that is, more than 50% by volume, preferably 90% by volume or more). ) An aqueous solvent such as a mixed solvent in which an organic solvent soluble in water is mixed at an arbitrary ratio can be used, and two or more kinds of mixed solvents may be used.

Since step 1 is a step of reacting 3-oxoadipic acid with hydrogen in the presence of a catalyst, a solvent that can dissolve 3-oxoadipic acid and is not hydrogenated under the reaction conditions of step 1 is used. This is preferable from the viewpoint of shortening the reaction time and suppressing by-products, and as such a solvent, an aqueous solvent or an organic solvent having a polarity value of 0 or more and 0.3 or less can be preferably used.

Here, the polarity value in the present specification, generally known as E _T ^N value, determined by utilizing the phenomenon that the maximum wavelength of the absorption spectrum of pyridinium -N- phenoxide betaine derivatives is significantly changed by the polarity of the solvent Water (1.000) and tetramethylsilane (0.000) are used as reference solvents, which are the polar parameters of the solvent (Chemical Handbook Basic Edition I, Revised 5th Edition, p. 770; Japan Chemical Society). , Maruzen Publishing Co., Ltd., 2004). For the polarity values of various solvents, for example, "Chemical Reviews, Vol. 94, No. 8, 2319-2358 (1994)" can be referred to, and the polarity values of the solvent having unknown polarity value and the mixed solvent can be referred to. It can be measured by the method described in the literature.

Examples of the organic solvent having a polarity value of 0 or more and 0.3 or less include n-pentane (0.006), n-hexane (0.009), n-heptane (0.012), n-octane (0.012), and the like. n-Nonan (0.009), n-decane (0.009), n-dodecane (0.012), cyclohexane (0.006), chloroform (0.259), bromoform (0.216), benzene ( 0.111), toluene (0.099), p-xylene (0.074), 3-ethyl-3-pentanol (0.241), 2,4-dimethyl-3-pentanol (0.290) , 3-Ethyl-2,4-dimethyl-3-pentanol (0.222), dimethyl ether (<0.2), diethyl ether (0.117), ethyl vinyl ether (0.170), di-n-propyl ether ( 0.102), di-n-butyl ether (0.071), tert-butyl methyl ether (0.124), dimethoxymethane (0.157), diethoxymethane (0.099), 1,2-dimethoxyethane (0.231), Diglycerum (0.244), Diethylene Glycol diethyl Ether (0.210), Triglym (0.253), Fran (0.164), tetrahydrofuran (0.207), Thiophen (0.145), Tetrahydrothiophene (0.185), tetrahydropyran (0.170), 1,4-dioxane (0.164), anisole (0.198), dibenzyl ether (0.173), diphenyl ether (0.142), 3-Pentanone (0.265), 2-hexanone (0.290), isobutylmethylketone (0.269), tert-butylmethylketone (0.256) diisopropylketone (0.247), di-n-butylketone (0.210), cyclopentanone (0.269), cyclohexanone (0.281), methyl acetate (0.253), ethyl acetate (0.228), vinyl acetate (0.225) n-propyl acetate (0.225) 0.210), n-butyl acetate (0.241), methyl acrylate (0.250), methyl methacrylate (0.222), dimethyl carbonate (0.232), diethyl carbonate (0.185), tert -Butylamine (0.179), diethylamine (0.145), triethylamine (0.043), trisn-butylamine (0.043), pyrrolidine (0.259) piperidine (0.148), carbon disulfide (0) .065) and so on. The numbers in parentheses indicate the polarity values.

Among organic solvents with a polarity value of 0 or more and 0.3 or less, ether solvents such as dimethyl ether, diethyl ether, 1,2-dimethoxyethane, diglyme, tetrahydrofuran, and dioxane, methyl acetate, ethyl acetate, n-propyl acetate, n-acetate A solvent mainly containing an ester solvent such as butyl can be preferably used, and in particular, a solvent mainly containing tetrahydrofuran, dioxane, 1,2-dimethoxyethane, digrim, and ethyl acetate can be more preferably used. Here, "mainly contained" means containing at a concentration of more than 50% by volume, preferably at a concentration of 90% by volume or more, and more preferably at a concentration of 100% by volume.

The polar values of the organic solvents used in the examples in the present specification are 0 or more and not 0.3 or less, respectively, of methanol (0.762), isopropanol (0.546), and tert-butanol (0.389). ). The numbers in parentheses indicate the polarity values.

The reaction temperature in step 1 is not limited, but is preferably 0 ° C. or higher and 100 ° C. or lower. When an aqueous solvent is used as the solvent, the reaction temperature is preferably 0 ° C. or higher and 50 ° C. or lower, and when an organic solvent having a polarity value of 0 or higher and 0.3 or lower is used as the solvent, the reaction temperature is preferably 0 ° C. or higher and lower than 75 ° C. In the case of any solvent, the reaction temperature is more preferably 10 ° C. or higher and 40 ° C. or lower. When the reaction temperature is raised, 3-oxoadipic acid tends to be thermally decomposed, while when the reaction temperature is too low, the reaction rate tends to decrease. In particular, it is convenient to carry out at room temperature, which does not require a device or operation for raising or cooling.

The metal contained in the catalyst used in step 1 is preferably a transition metal, and specifically, one selected from the group consisting of palladium, platinum, ruthenium, rhodium, renium, nickel, iridium, osmium, copper and chromium. Further, it is preferable that two or more kinds are contained.

The metal contained in the catalyst used in step 1 may be supported on a carrier from the viewpoint of saving the amount of metal used and increasing the catalytic activity. Examples of the carrier include carbon; alumina, shea silica, titania, zirconia, tantalum oxide, niobium oxide, zeolites, tungsten oxide, or metal oxides such as magnesia, silica-alumina composite oxides of these metal oxides, Examples thereof include silica titania, silica magnesia, and alumina zirconia. The ratio of the metal weight to the total weight of the metal supported on the carrier and the carrier is usually 0.1 to 10% by weight.

When the above-mentioned metal-supporting catalyst is used, it is preferable to heat-treat it in an inert gas such as nitrogen, helium, or argon or in a hydrogen atmosphere before the reaction to activate it before use.

Further, when the above-mentioned metal-supported catalyst is used, the catalyst can be easily recovered by solid-liquid separation after the reaction is completed. The recovered catalyst may be used repeatedly, and is preferably reactivated by heat treatment under an inert gas such as nitrogen, helium or argon or in a hydrogen atmosphere.

The partial pressure of hydrogen in step 1 is not particularly limited, but if the partial pressure of hydrogen is too low, the reaction time becomes long, while if the partial pressure of hydrogen is too high, it is not desirable for equipment safety. Therefore, 0.1 MPa or more and 10 MPa at room temperature. The following (gauge pressure) is preferable, and more preferably 0.5 MPa or more and 3 MPa or less (gauge pressure). The hydrogen used may be a mixed gas with an inert gas such as nitrogen, helium or argon.

The content of at least one selected from the group consisting of 3-oxoadipic acid and a salt thereof in the reaction mixture at the start of step 1 is not particularly limited, but is usually 0.1 to 50 per 100 parts by weight of the solvent. It is about parts by weight, preferably about 1 to 10 parts by weight.

The reaction of step 1 can be carried out by either a batch method or a continuous method.

3-Hydroxyadipic acid is a reaction intermediate in the method for producing ε-caprolactam of the present invention, which comprises steps 1 and 2. That is, as shown in Scheme 3, in the present invention, in step 1, a product containing 3-hydroxyadipic acid was obtained from 3-oxoadipic acid, and in step 2, ε-caprolactam was produced from 3-hydroxyadipic acid. To do.

In the production method of the present invention, it is important to once obtain 3-hydroxyadipic acid as a product of step 1 by performing step 1 and step 2 independently in order. Here, when the method described in Patent Document 3 is applied to 3-oxoadipic acid, 3-oxoadipic acid is subjected to the condition of coexisting with hydrogen and ammonia from the beginning of the reaction. In this case, As shown in Comparative Examples 1 and 2 described later, it is difficult to obtain the desired ε-caprolactam. This is thought to be because 3-oxoadipic acid is unstable to heat or ammonia. The method of the present invention differs from the method described in Patent Document 3 in that ammonia is not present in the first step 1. That is, step 1 is preferably performed in the substantially absence of ammonia. Here, "substantially in the absence" means that the ammonia concentration is 100 ppm or less, preferably 10 ppm or less, and most preferably 0 ppm.

By carrying out step 1, an unpurified product containing 3-hydroxyadipic acid, a by-product, a solvent, a catalyst and the like can be obtained. The unpurified product may be subjected to step 2 without any separation or purification operation. Alternatively, the catalyst and / or solvent may be roughly removed to obtain a crudely purified product containing 3-hydroxyadipic acid, which may be subjected to step 2. Alternatively, 3-hydroxyadipic acid may be isolated and purified from the crude product and subjected to step 2.

The removal of the catalyst can be carried out by ordinary unit operations such as extraction, adsorption, filtration, precipitation and centrifugation. Since the heterogeneous catalyst can be removed from the reaction solution by a simple solid-liquid separation operation such as filtration, precipitation, or centrifugation, use a heterogeneous catalyst when separating and purifying 3-hydroxyadipic acid after step 1. Is preferable from the viewpoint of ease of separation.

The removal of the solvent can be carried out by ordinary unit operations such as evaporation, drying, distillation and extraction. The removed solvent can be recycled and used in step 1.

As a method for isolating and purifying 3-hydroxyadipic acid from the crude product, ordinary methods such as extraction, membrane separation, column chromatography, ion exchange resin treatment, crystallization, and recrystallization can be used. ..

The 3-hydroxyadipic acid obtained in step 1 can be used in step 2 in a free form, in a salt state, converted to a carboxylic acid derivative (acid anhydride, ester, amide), or as a mixture thereof. Examples of 3-hydroxyadipic acid salts and carboxylic acid derivatives include 3-hydroxyadipic acid monoammonium salt, 3-hydroxyadipic acid monolithium salt, 3-hydroxyadipic acid monosodium salt, and 3-hydroxyadic acid monopotassium salt. Diammonium 3-hydroxyadipate, dilithium 3-hydroxyadipate, disodium 3-hydroxyadipate, dipotassium 3-hydroxyadipate, magnesium 3-hydroxyadipate, calcium 3-hydroxyadipate, 3-Hydroxyadipic acid anhydride, 3-hydroxyadipate monomethyl, 3-hydroxyadipate dimethyl, 3-hydroxyadipate monoethyl, 3-hydroxyadipic acid diethyl, 3-hydroxyadic acid monoamide, 3-hydroxyadic acid diamide, etc. Is exemplified.

In the production method of the present invention, 3-hydroxyadipic acid can be produced from 3-oxoadipic acid by the one-step step 1. The catalyst and solvent used in step 1 for producing 3-hydroxyadipic acid from 3-oxoadipic acid are used, but the solvent is the above-mentioned aqueous solvent or the above-mentioned aqueous solvent from the viewpoint of shortening the reaction time and suppressing by-products. It is preferable to use an organic solvent having a polarity value of 0 or more and 0.3 or less. When an aqueous solvent is used as the solvent, the reaction temperature is preferably 0 ° C. or higher and 50 ° C. or lower, and when an organic solvent having a polarity value of 0 or higher and 0.3 or lower is used as the solvent, the reaction temperature is 0 ° C. or higher and lower than 75 ° C. Is preferable.

Next, step 2 will be described. In step 2, at least one selected from the group consisting of 3-hydroxyadipic acid, which is the product of step 1, or a salt thereof or a carboxylic acid derivative thereof, or 3-hydroxyadipic acid, a salt thereof, and a carboxylic acid derivative thereof is hydrogen and React with ammonia.

In step 2, the reaction can be promoted by carrying out the reaction in the presence of a catalyst. As the catalyst, either a homogeneous catalyst or a heterogeneous catalyst can be used.

The metal contained in the catalyst is preferably a transition metal, and specifically, one or more selected from the group consisting of palladium, platinum, ruthenium, rhodium, renium, nickel, iridium, osmium, copper and chromium. It is preferable to include it.

The metal contained in the catalyst used in step 2 may be supported on a carrier from the viewpoint of saving the amount of metal used and increasing the catalytic activity. Examples of the carrier include carbon; alumina, shea silica, titania, zirconia, tantalum oxide, niobium oxide, zeolites, tungsten oxide, or metal oxides such as magnesia, complex oxides of these metal oxides (e.g. silica-alumina, Silica titania, silica magnesia, alumina zirconia). The ratio of the metal weight to the total weight of the metal supported on the carrier and the carrier is usually 0.1 to 10% by weight.

When the above-mentioned metal-supporting catalyst is used, it is preferable to heat-treat it in an inert gas such as nitrogen, helium, or argon or in a hydrogen atmosphere before the reaction to activate it before use.

When the above metal-supported catalyst is used, the catalyst can be easily recovered by solid-liquid separation after the reaction is completed. The recovered catalyst may be used repeatedly, and is preferably reactivated by heat treatment under an inert gas such as nitrogen, helium or argon or in a hydrogen atmosphere.

The partial pressure of hydrogen in step 2 is not particularly limited, but if the partial pressure of hydrogen is too low, the reaction time becomes long, while if the partial pressure of hydrogen is too high, it is not preferable for equipment safety. Therefore, 0.1 MPa or more and 10 MPa at room temperature. The following (gauge pressure) is preferable, and more preferably 0.5 MPa or more and 3 MPa or less (gauge pressure) at room temperature. The hydrogen used may be a mixed gas with an inert gas such as nitrogen, helium or argon.

Ammonia to be used may be added to the reaction vessel in either a gaseous state or a liquid state. When added to the reaction vessel in a liquid state, liquid ammonia or a solution in which ammonia is dissolved can be used. For example, an aqueous ammonia solution, an ammonia dioxane solution, an ammonia chloroform solution, an ammonia ether solution, an ammonia alcohol solution and the like can be used. When ammonia in a gaseous state is used, its partial pressure is not particularly limited, but if it is too low, the reaction time becomes long. Therefore, 0.1 MPa or more and 5 MPa or less (gauge pressure) at room temperature is preferable, and 0. It is 1 MPa or more and 1 MPa or less (gauge pressure).

Hydrogen and ammonia may be added to the reaction vessel individually or as a hydrogen / ammonia mixed gas prepared in advance. The order in which hydrogen and ammonia are added is not particularly limited.

The reaction temperature in step 2 is not limited, but is preferably 100 ° C. or higher and 350 ° C. or lower, and more preferably 150 ° C. or higher and 280 ° C. or lower. If the reaction temperature is low, the reaction tends not to proceed sufficiently, but if the reaction temperature is too high, by-production of compounds other than the target compound, ε-caprolactam, is promoted, and a sufficient yield may not be obtained. is there.

The solvent used in step 2 is not limited, but is an alcohol solvent such as methanol, ethanol, propanol and butanol, a halogen solvent such as carbon tetrachloride, dichloromethane and chloroform, and a fat such as pentane, hexane, heptane, octane and decane. Group hydrocarbon solvents, aromatic hydrocarbon solvents such as benzene, toluene, xylene, ether solvents such as dimethyl ether, diethyl ether, 1,2-dimethoxyethane, diglycim, tetrahydrofuran, dioxane, methyl acetate, ethyl acetate, acetic acid Ester-based solvents such as n-propyl and n-butyl acetate, γ-butyrolactone, N-methylpyrrolidone, dimethylsulfoxide, water and the like can be used, and two or more of these may be mixed solvents. Preferably, an aprotic solvent such as dioxane, diglyme or tetrahydrofuran is used.

The content of 3-hydroxyadipic acid, a salt thereof or a carboxylic acid derivative thereof or a mixture thereof in the reaction mixture at the start of step 2 is not particularly limited, but is usually 0.1 to 10 parts by weight based on 100 parts by weight of the solvent. About parts, preferably about 1 to 5 parts by weight.

The reaction of step 2 can be carried out by either a batch method or a continuous method.

Steps 1 and 2 can be continuously carried out in the same reactor (one-pot). It is preferable to carry out the reaction in the same reactor from the viewpoint of equipment.

When steps 1 and 2 are continuously carried out in the same reactor, the catalyst used in step 1 can be carried out as it is without being taken out from the reactor. Further, another catalyst may be added to the catalyst used in step 1, or the catalyst used in step 1 may be removed and replaced with another catalyst. Of these, it is convenient and economical to use in step 2 without taking out the catalyst used in step 1.

When step 1 and step 2 are continuously carried out in the same reactor, step 2 can be carried out without taking out the solvent used in step 1. Further, another solvent may be added to the solvent used in step 1, or the solvent used in step 1 may be removed and replaced with another solvent. Of these, it is convenient and economical to use in step 2 without taking out the solvent used in step 1.

When steps 1 and 2 are continuously carried out in the same reactor, the hydrogen remaining in the reactor after the completion of step 1 can be added to step 2 without being released to the outside of the reactor. .. Further, the hydrogen remaining in the reactor in the step 1 may be released to the outside of the reactor, and then hydrogen and ammonia may be newly added to carry out the step 2, and the nitrogen, helium, argon and the like may be added. After substituting for activity, hydrogen and ammonia may be newly added to carry out step 2.

In the method for producing ε-caprolactam of the present invention, ε-caprolactam can be recovered by ordinary separation and purification operations such as filtration, extraction and distillation after the completion of step 2. Hydrogen and ammonia can be recycled into the reaction system.

The ε-caprolactam obtained by the method for producing ε-caprolactam of the present invention can be used as a raw material for producing polyamide. As a method for producing a polyamide, a known method for ring-opening polymerization of ε-caprolactam can be applied (see Osamu Fukumoto, "Polyamide Resin Handbook", Nikkan Kogyo Publishing Co., Ltd. (January 1998)).

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples.

In Examples 1-8 and Comparative Examples 1 and 2, the product yield, which is the reaction result, was calculated by the following formula (1). The raw material means 3-oxoadipic acid.
Formula (1) Product yield (mol%) = Product yield (mol) / Raw material charge amount (mol) x 100.

In Examples 9-24, the raw material conversion rate and the product selectivity, which are the reaction results, were determined by the following formulas (2) and (3), respectively. The raw material means 3-oxoadipic acid.
Formula (2) Raw material conversion rate (mol%) = Raw material consumption (mol) / raw material charge (mol) x 100.
Formula (3) Product selectivity (mol%) = product yield (mol) / raw material consumption (mol) x 100.

The reaction solution was analyzed by gas chromatography (GC) and high performance liquid chromatography (HPLC). The quantification of the product was performed by an absolute calibration curve prepared using the standard. Quantitative analysis of ε-caprolactam was performed by GC, and quantitative analysis of 3-oxoadipic acid, 3-hydroxyadipic acid, and levulinic acid was performed by HPLC. The analysis conditions for GC and HPLC are shown below.

GC analysis conditions GC equipment: GC2010 plus (manufactured by Shimadzu Corporation)
Column: InertCap for amines, length 30 m, inner diameter 0.32 mm (manufactured by GL Science)
Carrier gas: helium, constant linear velocity (40.0 cm / sec)
Vaporization chamber temperature: 250 ° C
Detector temperature: 250 ° C
Column oven temperature: 100 ° C → (10 ° C / min) → 230 ° C 3 minutes (16 minutes in total)
Detector: FID.

HPLC analysis conditions HPLC equipment: Prominence (manufactured by Shimadzu Corporation)
Column: Synergy hydro-RP (manufactured by Phenomenex), length 250 mm, inner diameter 4.60 mm, particle size 4 μm
Mobile phase: 0.1 wt% aqueous phosphoric acid solution / acetonitrile = 95/5 (volume ratio)
Flow velocity: 1.0 mL / min Detector: UV (210 nm)
Column temperature: 40 ° C.

Reference Example 1 Preparation of 3-oxoadipic acid The 3-oxoadipic acid used in the present invention was prepared by chemical synthesis.

First, 1.5 L of ultra-dehydrated tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) was added to 13.2 g (0.1 mol) of succinic acid monomethyl ester (manufactured by Wako Pure Chemical Industries, Ltd.), and 16.2 g (0. 1 mol) (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred at room temperature for 1 hour in a nitrogen atmosphere. To this suspension, 15.6 g (0.1 mol) of malonic acid monomethyl ester potassium salt and 9.5 g (0.1 mol) of magnesium chloride were added, and the mixture was stirred at room temperature for 1 hour under a nitrogen atmosphere, and then at 40 ° C. for 12 hours. Stirred. After completion of the reaction, 0.05 L of 1 mol / L hydrochloric acid was added at room temperature, extracted with ethyl acetate, and separated and purified by silica gel column chromatography (hexane: ethyl acetate = 1: 5) to obtain pure 3-oxohexane. 13.1 g of dicarboxylic acid dimethyl ester was obtained. Yield 70%.

To 5 g (0.026 mol) of the obtained 3-oxohexanedicarboxylic acid dimethyl ester, 26 mL of methanol (manufactured by Kokusan Kagaku Co., Ltd.) was added, 12 mL of a 5 mol / L sodium hydroxide aqueous solution was added with stirring, and the mixture was stirred overnight at room temperature. did. After completion of the reaction, 12 mL of 5 mol / L hydrochloric acid was added, and the mixture was extracted with 100 mL of ethyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.). After concentration on a rotary evaporator, it was recrystallized from acetone / petroleum ether to obtain 2 g of pure 3-oxoadipic acid. Yield 47%.

Example 1
Two steps, a step of mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen (step 1) and a step of reacting the product of step 1 with hydrogen and ammonia (step 2), are carried out in order. Manufacturing process of ε-caprolactum according to
0.15 g of 3-oxoadipic acid synthesized in the reference example, 50 mL of dioxane (manufactured by Wako Pure Chemical Industries, Ltd.), Palladium, 5% on gamma aluminum powder in a stainless steel autoclave (manufactured by pressure-resistant glass industry) with an internal capacity of 0.1 L. , Reduced (manufactured by Alfa Aesar) and 0.2 g of 5% Pt alumina powder (manufactured by N.E. Chemcat) were added. After purging the inside of the autoclave with nitrogen, hydrogen gas was added so that the internal pressure of the autoclave was 0.9 MPa (gauge pressure), and then the mixture was stirred at 500 rpm for 24 hours at room temperature. The gas in the autoclave was released and returned to normal pressure. A part of the reaction solution was sampled and analyzed by HPLC. The results are shown in Table 1.

Process 2
After step 1, ammonia gas was added so that the internal pressure of the autoclave was 0.18 MPa (gauge pressure), and then the mixture was stirred at 500 rpm for 45 minutes at room temperature. Hydrogen was added while continuing stirring, and the internal pressure of the autoclave was adjusted to 0.72 MPa (gauge pressure) in terms of partial pressure of hydrogen (total pressure (gauge pressure): 0.9 MPa). Then, the temperature in the autoclave was raised to 250 ° C. over 15 minutes. After holding at 250 ° C. for 7 hours, the mixture was allowed to cool to room temperature, the gas in the autoclave was released to return to normal pressure, and then the reaction solution was recovered. 50 mL of water was added and mixed, the catalyst was removed by centrifugation and the supernatant was analyzed by GC and HPLC. The results are shown in Table 1.

Comparative Example 1
Reaction of 3-oxoadipic acid with hydrogen and ammonia by the method disclosed in Patent Document 3 3-oxoadipine synthesized in Reference Example 1 in a stainless steel autoclave (manufactured by Pressure Resistant Glass Industry Co., Ltd.) having an internal volume of 0.1 L. 0.15 g of acid, 50 mL of dioxane (manufactured by Wako Pure Chemical Industries, Ltd.), Palladium, 0.05 g of 5% on gumma alumina hydrogen, reduced (manufactured by Alfa aesar) were added. After purging the inside of the autoclave with nitrogen, ammonia gas was added to adjust the internal pressure of the autoclave to 0.18 MPa (gauge pressure), and then the mixture was stirred at room temperature at 500 rpm for 45 minutes. Hydrogen was added while continuing stirring, and the internal pressure of the autoclave was adjusted to 0.72 MPa (gauge pressure) in terms of partial pressure of hydrogen (total pressure (gauge pressure): 0.90 MPa). Then, the temperature in the autoclave was raised to 250 ° C. over 1 hour. After holding at 250 ° C. for 3 hours, the mixture was allowed to cool to room temperature, the gas in the autoclave was released to return to normal pressure, and then the reaction solution was recovered. 50 mL of water was added and mixed, the catalyst was removed by centrifugation and the supernatant was analyzed by GC and HPLC. The results are shown in Table 1.

Comparative Example 2
Reaction of 3-oxoadipic acid with hydrogen and ammonia using the same raw materials, solvent, and catalyst as in Example 1 in the same manner as in Comparative Example 1. Stainless steel autoclave with a content of 0.1 L (pressure resistant glass industry) 3-Oxoadiponic acid 0.15 g, dioxane 50 mL (manufactured by Wako Junyaku Co., Ltd.), 5% Pd alumina powder (palladium, 5% on gumma alumina hydrogen, redened (manufactured by Alfa aeasar)) synthesized in Reference Example 1 )) 0.05 g and 0.2 g of 5% Pt alumina powder (manufactured by NE Chemcat) were added. After purging the inside of the autoclave with nitrogen, ammonia gas was added to adjust the internal pressure of the autoclave to 0.18 MPa (gauge pressure), and then the mixture was stirred at room temperature at 500 rpm for 45 minutes. Hydrogen was added while continuing stirring, and the internal pressure of the autoclave was adjusted to 0.72 MPa (gauge pressure) in terms of partial pressure of hydrogen (total pressure (gauge pressure): 0.9 MPa). Then, the temperature in the autoclave was raised to 250 ° C. over 15 minutes. After holding at 250 ° C. for 6 hours, the mixture was allowed to cool to room temperature, the gas in the autoclave was released to return to normal pressure, and then the reaction solution was recovered. 50 mL of water was added and mixed, the catalyst was removed by centrifugation and the supernatant was analyzed by GC and HPLC. The results are shown in Table 1.

Reference example 2
Preparation nitrate palladium catalyst a _{(Pd (NO 3) 2 ·} 2H 2 O (0.13g) in aqueous solution dissolved in water 10 mL, niobium oxide _(Nb 2 _{O 5,} was added manufactured by Wako Pure Chemical Industries, Ltd.) 1 g, room temperature The water was evaporated at 20 mmHg and 40 ° C. using an evaporator, and the obtained powder was dried at 110 ° C. overnight and then fired at 500 ° C. for 4 hours under air flow. Was treated at 400 ° C. for 2 hours under hydrogen flow to obtain 5% Pd-supported niobium oxide (Pd / Nb ₂ O ₅ ). Here, 5% means that Pd and the carrier were charged at the time of raw material preparation. It means that the ratio of Pd to the sum of the weight is 5% by weight. Similarly, the carrier is tantalum oxide (Ta ₂ O ₅ , manufactured by Wako Pure Chemical Industries, Ltd.), zirconia (ZrO ₂ , JRC-ZRO-3, catalyst). reference catalyst) using Society, 5% Pd supported tantalum oxide _{(Pd / Ta 2 O 5)} , 5% Pd supported zirconia (Pd / ZrO ₂₎ was prepared.

Example 2
Using 0.1 g of 5% Pd-supported niobium oxide and 0.03 g of 5% Pt-supported carbon (Platinum on carbon, 5 wt.% Loading, matrix activated carbon support; manufactured by Sigma Aldrich) prepared in Reference Example 2 as a catalyst. The reaction was carried out in the same manner as in Example 1 except that the reaction temperature in step 1 was set to 30 ° C. and the reaction time was set to 14.5 hours, and the reaction was held at 250 ° C. for 6 hours in step 2. The results are shown in Table 1.

Example 3
Using 0.1 g of 5% Pd-supported tantalum oxide and 0.025 g of 5% Pt-supported carbon prepared in Reference Example 2 as a catalyst, the reaction time in step 1 was set to 19 hours, and the reaction time in step 2 was maintained at 250 ° C. for 4 hours. The reaction was carried out in the same manner as in Example 2 except that. The results are shown in Table 1.

Example 4
Using 0.1 g of 5% Pd-supported zirconia prepared in Reference Example 2 in place of 5% Pd-supported niobium oxide, and using 1,2-dimethoxyethane (manufactured by Wako Pure Chemical Industries, Ltd.) as a solvent instead of dioxane, The reaction was carried out in the same manner as in Example 2 except that the reaction time of step 1 was set to 18 hours and the reaction was held at 250 ° C. for 5 hours in step 2. The results are shown in Table 1.

Example 5
Using Palladium, 5% on gumma aluminum powder, reducated (manufactured by Alfa Aesar) 0.1 g and 5% Pt-supported carbon 0.05 g as the catalyst, the reaction time of step 1 was set to 14.5 hours, and in step 2. The temperature in the autoclave was raised to 180 ° C. over 15 minutes and held for 1 hour, then raised to 250 ° C. over 8 minutes and held at 250 ° C. for 4.7 hours, as in Example 2. The reaction was carried out by the method. The results are shown in Table 1.

Example 6
Using 0.2 g of 5% Pd-supported niobium oxide and 0.05 g of 5% Pt-supported carbon as the catalyst, the reaction time in step 1 was set to 16 hours, and the temperature in the autoclave was raised to 180 ° C. over 15 minutes in step 2. After the temperature was raised and held for 2 hours, the temperature was raised to 250 ° C. over 8 minutes, and the reaction was carried out in the same manner as in Example 2 except that the temperature was raised to 250 ° C. for 8 hours. The results are shown in Table 1.

Example 7
In step 2, the temperature inside the autoclave was raised to 150 ° C. over 10 minutes and held for 1 hour, then raised to 200 ° C. over 8 minutes and held for 1 hour, and then raised to 250 ° C. over 8 minutes. The reaction was carried out in the same manner as in Example 6 except that the mixture was warmed and kept at 250 ° C. for 20 hours. The results are shown in Table 1.

Example 8
0.2L stainless steel autoclave (manufactured by Pressure Resistant Glass Industry Co., Ltd.), 3-oxoadipic acid 0.3g, dioxane 100mL (manufactured by Kanto Chemical Co., Inc.), Palladium, 5% on gamma aluminum hydrogen, reduced (manufactured by Alfa Aesar) ) with 0.1g and 5% Pt on carbon containing (manufactured by NE Chemcat Co.) 0.2 g, at step 1, 1.45 MPa of hydrogen gas pressure (gauge pressure) at 30 ° C., 7 hours at 1000rpm After stirring, the internal pressure of ammonia gas was set to 0.05 MPa (gauge pressure), the stirring speed was set to 1000 rpm, and the hydrogen partial pressure was set to 1.45 MPa (gauge pressure) in step 2 (total pressure (gauge pressure): 1.5 MPa). The reaction was carried out in the same manner as in Example 1 except that the temperature in the autoclave was raised to 250 ° C. over 1 hour and kept at 250 ° C. for 3 hours. The results are shown in Table 1.

Example 9
Production of 3-hydroxyadipic acid by mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen 3-Synthesized as a reference example in a stainless steel autoclave (manufactured by Pressure Resistant Glass Industry Co., Ltd.) with an internal volume of 30 mL 16 mg of oxoadipic acid, 10 mL of water, and 10 mg of 5% Pt-supported carbon (Platinum on carbon, 5 wt.% Loading, catalyst activated carbon support; manufactured by Sigma Aldrich) were added. After purging the inside of the autoclave with nitrogen, hydrogen gas was added so that the internal pressure of the autoclave was 0.9 MPa (gauge pressure), and then the reaction was carried out by stirring at 500 rpm for 1 hour at room temperature. The gas in the autoclave was released and returned to normal pressure. The reaction solution was analyzed by HPLC. The results are shown in Table 2.

Example 10
The reaction was carried out in the same manner as in Example 9 except that the reaction temperature was set to 40 ° C. The results are shown in Table 2.

Example 11
The reaction was carried out in the same manner as in Example 9 except that the reaction temperature was set to 60 ° C. The results are shown in Table 2.

Example 12
The reaction was carried out in the same manner as in Example 9 except that the reaction temperature was set to 80 ° C. The results are shown in Table 2.

Example 13
The reaction was carried out in the same manner as in Example 9 except that the reaction time was set to 24 hours using 5% Pt-supported alumina (manufactured by N.E. Chemcat) as a catalyst. The results are shown in Table 2.

Example 14
The reaction was carried out in the same manner as in Example 9 except that the solvent was dioxane (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

Example 15
The reaction was carried out in the same manner as in Example 14 except that the reaction temperature was set to 40 ° C. The results are shown in Table 2.

Example 16
The reaction was carried out in the same manner as in Example 14 except that the reaction temperature was set to 60 ° C. The results are shown in Table 2.

Example 17
The reaction was carried out in the same manner as in Example 14 except that the reaction temperature was set to 80 ° C. The results are shown in Table 2.

Example 18
The reaction was carried out in the same manner as in Example 14 except that the reaction temperature was set to 120 ° C. The results are shown in Table 2.

Example 19
The reaction was carried out in the same manner as in Example 9 except that the solvent was tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

Example 20
The reaction was carried out in the same manner as in Example 9 except that the solvent was ethyl acetate (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

Example 21
The reaction was carried out in the same manner as in Example 9 except that the solvent was methanol (manufactured by Kokusan Kagaku Co., Ltd.). The results are shown in Table 2.

Example 22
The reaction was carried out in the same manner as in Example 9 except that the solvent was isopropanol (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

Example 23
The reaction was carried out in the same manner as in Example 9 except that the solvent was tert-butyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.). The results are shown in Table 2.

Example 24
The reaction was carried out in the same manner as in Example 14 except that 5% Rh-supported carbon (Rhodium on carbon, 5 wt.% Loading; manufactured by Sigma-Aldrich) was used as a catalyst. The results are shown in Table 2.

In Examples 1-8, a step of mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen (step 1) and a step of reacting the product of step 1 with hydrogen and ammonia (step 2) are carried out. As a result, ε-caprolactam could be obtained from 3-oxoadipic acid. Further, in step 1, 3-hydroxyadipic acid was obtained from 3-oxoadipic acid, and in step 2, 3-hydroxyadipic acid was consumed to obtain ε-caprolactam. It was found to be an intermediate in the production method of the invention.

On the other hand, in Comparative Example 1, 3-oxoadipic acid was reacted with hydrogen from the beginning under the condition that ammonia coexisted as in the method described in Patent Document 3, but ε-caprolactam was not produced.

Further, from Comparative Example 2, even if the same catalyst and solvent as in Example 1 are used, 3-oxoadipic acid is reacted with hydrogen under the condition that ammonia coexists from the beginning as in the method described in Patent Document 3. Did not produce ε-caprolactam

From the above, when 3-oxoadipic acid is used as a raw material, step 1 is performed under the condition that ammonia does not coexist, and step 2 is a condition under which ammonia coexists after obtaining 3-hydroxyadipic acid as an intermediate. It was shown that it is important to carry out.

From Examples 9-24, it was shown that 3-hydroxyadipic acid can be produced by mixing 3-oxoadipic acid with a catalyst and a solvent in the presence of hydrogen.

From Example 9-12, by mixing 3-oxoadipic acid with a catalyst in the presence of hydrogen in an aqueous solvent under the conditions of a reaction temperature of 0 ° C. or higher and 50 ° C. or lower, while suppressing the by-production of levulinic acid, It was shown that 3-hydroxyadipic acid can be produced.

From Examples 13-16, 19 and 20, 3-oxoadipic acid is mixed with a catalyst in the presence of hydrogen in an organic solvent having a polarity value of 0 or more and 0.3 or less under a reaction temperature of 0 ° C. or more and less than 75 ° C. This showed that 3-hydroxyadipic acid could be produced while suppressing the by-production of levulinic acid.

Claims (11)

A step of mixing at least one selected from the group consisting of 3-oxoadipic acid and salts thereof with a catalyst and a solvent in the presence of hydrogen and in the substantially absence of ammonia to produce 3-hydroxyadipic acid. A method for producing ε-caprolactam, which comprises step 1 and step 2 which is a step of reacting 3-hydroxyadipic acid, a salt or a carboxylic acid derivative thereof, which is a product of step 1, or a mixture thereof with hydrogen and ammonia. The method according to claim 1, wherein the solvent is an aqueous solvent or an organic solvent having a polarity value of 0 or more and 0.3 or less. The method according to claim 1 or 2, wherein the solvent is an organic solvent mainly containing at least one selected from the group consisting of an ether solvent and an ester solvent. The method according to any one of claims 1 to 3, wherein the solvent is an organic solvent mainly containing at least one selected from tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diglyme, and ethyl acetate. The method according to any one of claims 1 to 4, wherein the step 1 is performed under the conditions shown in (i) or (ii) below.
(I) Reaction temperature 0 ° C or higher and 50 ° C or lower in an aqueous solvent (ii) Reaction temperature 0 ° C or higher and lower than 75 ° C in an organic solvent with a polarity value of 0 or higher and 0.3 or lower. The method according to any one of claims 1 to 5, wherein the step 2 is performed in the presence of a catalyst. 1. The catalyst of steps 1 and / or 2 comprises one or more metals selected from the group consisting of palladium, platinum, ruthenium, rhodium, rhenium, nickel, iridium, osmium, copper and chromium. The method according to any one of 6 to 6. The production method according to claim 7, wherein the metal is supported on at least one carrier selected from the group consisting of alumina, carbon, silica, titania, zirconia, tantalum oxide, niobium oxide, and zeolite. The production method according to any one of claims 1 to 8, wherein the partial pressure of hydrogen in steps 1 and 2 is 0.1 MPa or more and 10 MPa or less at room temperature and gauge pressure. The production method according to any one of claims 1 to 9, wherein the reaction temperature in the step 2 is 150 ° C. or higher and 280 ° C. or lower. Mixing at least one selected from the group consisting of 3-oxoadipic acid and salts thereof with the catalyst in the presence of hydrogen and in the substantially absence of ammonia under the conditions shown in (i) or (ii) below. 3-Hydroxyadipic acid production method.
(I) Reaction temperature 0 ° C or higher and 50 ° C or lower in an aqueous solvent (ii) Reaction temperature 0 ° C or higher and lower than 75 ° C in an organic solvent with a polarity value of 0 or higher and 0.3 or lower.